My son give me a iphone 6 but the front screan is locked i want to factory reset

You can resort to iTunes to restore iPhone to factory settings. Just follow below steps to do that.

Restoring iPhone to Factory Settings with iTunes

iTunes enables users to back up data to iTunes and restore iPhone to factory settings. Before you start restoring iPhone to factory settings, please note that you need to install the latest version of iTunes on your PC or MAC. Then go to Settings > iCloud to turn off Find My iPhone. Now, the detailed restoring steps are as follows.
1. Plug iPhone into the computer with the USB cable. The iTunes on your computer will automatically launch. If not, double-click the icon to start it.
2. Click the name of your iPhone at the upper right corner of iTunes, and then the information of your iPhone will be shown. Click the "Restore iPhone" button in the window to start.
3. iTunes will ask whether you want to back up iPhone before restoring. You'd better choose "Yes" for the reset will erase the contents in your iPhone. Then iTunes will start restoring your iPhone to factory settings.

3. Click Restore again to confirm. Then iTunes erases your iPhone and installs the latest iOS or iPod software. After you restore your iPhone to factory settings, it will restart. Now you can set it up as new.

For more methods, check: How Do I Restore My iPhone to Factory Settings

Check youtube.

Apple's instructions here.
https://support.apple.com/en-us/HT204306

Reset iPhone 5. Reset iPhone 5: Press and hold the On/Off Sleep/Wake button and the Home button at the same time for at least ten seconds, until the Apple logo appears.

I suggest you can approach Unlocking4u.com and specify the country,locked network of iPhone 6 .Based on the availability you can get the permanent unlock service along with free instructions.

I'm so sorry for your loss. I can help you set the device back to factory, but cracking passcodes is tough.

My suggestion is to reset the phone to factory settings. I am not sure what device you have, so I'll give instructions for both. If I find a way to get through the passcode in the next couple hours I'll post a second answer. If you let us know the type of phone and model that would help.

Android...
iPhone... (Use iTunes to restore your iPhone iPad or iPod to factory settings)

On your iPhone, go to Settings, then General. Tap on Reset. You should see three different options to choose from.

To proceed, tap on Reset All Settings. Be careful not to tap 'Erase All Content and Settings'

Your iPhone's settings should be back to its original configuration without you having to lose all your data and restore them at a later time.

If you want to reset iPhone data settings, there are several different ways you to follow. I will show you one of them.

iTunes enables you to restore iPhone 6 Plus to factory settings. Before you start restoring iPhone to factory settings, please note that you need to install the latest version of iTunes on your PC or MAC. Then go to Settings > iCloud to turn off Find My iPhone. Now, you can factory reset your iPhone 6 Plus with iTunes as follows.
1. Plug iPhone 6 Plus into the computer with the USB cable. The iTunes on your computer will automatically launch. If not, double-click the icon to start it.
2. Click the name of your iPhone 6 Plus at the upper right corner of iTunes, and then the information of your iPhone 6 Plus will be shown. Click the "Restore iPhone" button in the window to start.
3. iTunes will ask whether you want to back up iPhone 6 Plus before restoring. You'd better choose "Yes" for the reset will erase the contents in your iPhone 6 Plus. Then iTunes will start restoring your iPhone 6 Plus to factory settings.

3. Click Restore again to confirm. Then iTunes erases your iPhone 6 Plus and installs the latest iOS software. After you restore your iPhone 6 Plus to factory settings, it will restart. Now you can set it up as new.


For more methods, check: How to Restore iPhone to Factory Settings

To recover a locked iPhone iOS Forgotten passcode or device disabled after entering wrong passcode

You will also be able to reset iPhone to factory settings within your iPhone. You just need to go to "Settings > General > Reset" and then choose the categories you want to reset and then apply it. If you choose "Reset All Contents and Settings", then you will get all the files in your iPhone erased.

Once you tap on "Erase All Content and Settings", you will be asked to enter your Apple ID password. Next, you will see a Popup Message informing you that All media, data and settings will be erased from your iPhone. Click on Erase iPhone to factory reset iPhone 6 Plus.

Apart from above methods, you can also try the methods in this guide. How to Restore iPhone 6 Plus to Factory Settings